Originally Posted by
jfmckenna
I'll add to that, what did people use back in the day to climb? I don't see many vintage 5 speed freewheels with a 26 or 28 cog though I imagine they had to exist. I understand that the NR derailleur on my bike is rated to a 26 but some people have managed to get a 28 to work. I think a 26 would be ok for me but the 28 would really sweeten the ride.
Sixes were widely available in the mid-70s and Hyperglide came out around 1977 or so. That meant six cogs on a 120 mm axle and seven on 126.5. I believe the European manufacturers were a year or two behind SunTour and Shimano in adopting the narrow spacing.
Back in the day, nearly everyone was still over-geared, even with the extra cogs. 13-21 was pretty standard, with maybe a 13-23 called out for a super steep day. You wanted single-step for at least the first four cogs.
So don't sweat, seven speed is period-correct for you Guerciotti. Of course, you've probably been using incorrect eight speed chains for the last ten years. If you spread your chainstays, be aware that dropout alignment may be affected.